TMI licensed for 20 more years

23 October 2009

The operating licence for Unit 1 of the Three Mile Island (TMI) nuclear power plant in Pennsylvania has been renewed for a further 20 years by the US Nuclear Regulatory Commission (NRC).


Exelon's TMI plant (Image: NRC)
The original licence for reactor - a 852 MWe pressurized water reactor (PWR) which began operating in September 1974 - was due to expire on 19 April 2014, but the NRC has now extended the licence for a further 20 years, until 2034.


Commercial power reactors in the US were originally licensed by the NRC for up to 40 years of operation under the terms of the country's Nuclear Energy Act. Operators can apply for their licences to be renewed for up to a further 20 years in a two-track process that reviews both safety and environmental issues as well as including public participation.


The NRC's environmental review for the licence renewal concluded that there were no environmental impacts that would preclude renewal of TMI's licence for environmental reasons. After reviewing the plant's safety systems and specifications, the NRC also concluded that there were no safety concerns that would preclude licence renewal.


Exelon, which owns and operates the unit, submitted its licence renewal in January 2008. The company said that its workers collectively spent 60,000 hours preparing the 2550-page licence renewal application.


TMI is the 55th US reactor to have its operating licence renewed by the NRC. A further 13 applications for a total of 20 reactors are currently under review by the commission.


Exelon said that over the past five years it "has invested more than $500 million into plant equipment to ensure continued safe operation and to ensure essential electricity is supplied to the region." It added, "This year, TMI will complete its largest capital project to date, when new replacement steam generators are installed in the plant."


Earlier this month, Areva delivered two replacement steam generators for use in TMI. The new steam generators will be installed later this year during a scheduled refuelling outage. In addition, new control rod drive mechanisms will be installed.